Copenhagen
Copenhagen got its first metro lines in 2002, when M1 and M2 opened, though the S-tog commuter trains, running since 1934, had long been the backbone of rail in the city. The metro is fully driverless and runs 24 hours a day, every day of the year. In the twenty years since, the network has kept growing. The metro reached Copenhagen Airport in 2007, and the M3 City Circle Line opened in 2019, linking the central districts in a loop, followed by the M4 to Nordhavn in 2020, which was extended to Sydhavn in 2024.
